with the best intentions and all efforts, president clinton vowed that north korea won't go nuclear. why is this nuclear deal different than any other nuclear deal? [laughter.] >> well, we don't know yet. no, we don't know yet. i think it's important for everybody to understand this is hard. because the technology of the nuclear cycle, you can get off the internet -- the knowledge of creating a nuclear weapons is already out there. and iran is a large country and it is a relatively wealthy country, and so we have to take seriously the possibility that they are going to try to get a nuclear weapon. that's what this whole exercise is about. having said that, if you look at the history, by the time we got an agreement with north korea, they essentially already had a nuclear weapon. with respect to pakistan, there was never the kinds of inspection regimes and international sanctions and u.n. resolutions that were in place. we have been able to craft an international effort and verification mechanism around the iran nuclear program that is unprecedented and unique. that doesn't mean it's